Aluminum foam facades: why a cellular metal belongs outside

A facade panel has one job that lasts a few seconds at the opening party and another that lasts forty years. The first is to look right. The second is to keep looking right through rain, sun, freeze-thaw, and whatever the building code asks of it. Aluminum foam is interesting on the first count because of its surface, and on the second because of what it is made of.

Metal through the full thickness

Most textured cladding is a system: a face material, a backing, an adhesive, a coating. Each interface is a place where weather gets in. An aluminum foam panel is one material. The texture is not applied; it is the section of the material itself. There is no skin to delaminate and no paint film to chalk or peel. The surface weathers the way bare aluminum weathers, by forming its own thin oxide layer and then stopping.

Non-combustible

Aluminum is a non-combustible material. For exterior walls, where codes have tightened sharply since the cladding fires of the last decade, that is often the first question an architect has to answer before any conversation about appearance. Aluminum foam answers it with the material rather than with a treatment. The fire rating of a complete wall assembly still depends on everything else in it, and is documented per project.

Light enough to simplify the structure

A foam panel weighs a fraction of a solid aluminum plate of the same size. On a facade that shows up as lighter sub-framing, smaller fixings, and easier handling on site. On a retrofit over an existing wall, it can be the difference between a cladding that the structure accepts and one it does not.

A surface that reads at every distance

From across the street, fine-cell panels read as a soft, even metal field that changes with the light. At the entrance, the cells become visible and the material becomes something people touch. Coarse-cell panels do the opposite: they are sculptural from a distance and almost geological up close. Mixing grades on one elevation is a legitimate move, because the panel system and the detailing stay the same.

Detailing notes

• Panels are sawn to size. Edges can be left raw, which shows the cell structure in section, or closed with an aluminum angle or channel.
• Fix mechanically through the panel or with a concealed rail; the material takes screws and rivets without special inserts.
• Natural variation between panels is part of the surface. Lay out panels from several billets across an elevation rather than in billet order.
• Rainscreen principles apply as they would to any metal panel: ventilated cavity, drained joints, no reliance on sealant.

What to ask for

Start with the three grades in hand, then decide which one carries the elevation. For a project, VORALOY documents panel dimensions, weight, and finish, and ties assembly performance to tested build-ups. See Applications for the other places the material is used.

Hold the material before you decide. The Standard Sample Kit is one 300 × 300 × 20 mm panel; the Designer Kit is three cell grades side by side. Both ship free within the United States.